This is my initial work of UI generalization. As we now get GTK2 support onperf report, improve setup_browser() to handle it properly so that we canadd various UI specific initialization codes to the function. At least, weneed basic error/warning handlers ASAP to see what's going on when an erroroccurred, IMHO.

I put new file setup.c under ui directory (not under util/ui) and it may ormay not be compiled depending on the system configuration. I think it'd bebetter moving generic UI codes to the directory and TUI specific codes toui/tui, and so on, so that the util directory doesn't contain any UI codes.But before proceeding, I'd like to listen to your opinions :).